Lower build

[Dayman]

I now have a stripped lower, lower parts kit, and stock assembly. I bought a wrench to install the buffer tube. After watching videos on lpk install looks like I need punches too. I really don't want to buy anymore tools, probably won't build another for awhile. I have read on some other sights where you can use pliers to install roll pins, I really don't want to screw up my lower. Anyone try this? Should i just fork out for tools? Anyone wanna lone tools (rent)? Or better yet anyone wanna help me put this thing together right? Located in travelers rest. Thanks for any replies

 

[94formulabird]

put painters/masking tape on the lower and use vice grips to slowly insert the pins...wrap the vice grips with tape as well to ensure the pins arent chewwed up on the ends...thats how i did it...

 

[Tigerstripe]

cut the end off a small screw driver, abra kadabra, punch. good enough for the pins. it doesnt take a 2 lb hammer.

id be happy to help but im in Enoree. ive put them together sitting in the swing on the porch. when do you work, maybe we could meet.

3 things you might want before assembly.

1 anti roll pins, but they are easy to add later. $30 and tax

2 the plate that goes under the castle nut. if you want one with a place to hook up a sling. also not hard later. around $12 +tax?

3 a magpul inlarged trigger under enclosure type doohickey. bigger hole for finger with gloves. also not hard to add later. $12=tax?

or not.

 

[Dayman]

Thanks for the reply

I have a set of small torx screw drivers which are pretty flat on the end so they may work as a punch if not i'll just cut a screw driver.
I will stop in the lgs today and see if the have the anti roll pins, if not i will just in stall what I have. Might as well go ahead and pick up the magpul trigger guard and moe grip too :mrgreen: . The stock kit i picked up had the sling attchment already. Thanks for the help!

 

[Dayman]

Started my lower build tonight. Started smooth enough but I have hit a bit of a snag. The bolt catch is crazy tight, I mean like I have to hammer it into the reciever. What should I do cause, as is is not going to work. I guess I will try a new catch if I can find one tomorrow. If that doesn't work I guess I'll file down the catch. Any help welcome. It's a palmetto state lower and spikes lpk fwiw.

 

[Dayman]

Said screw it and broke out the dremel. Got it to slide in and out smoothly with out being to loose. Just took out and hit with valspar spray paint. Paint is from last year so I hope it holds up. Will check the fit after paint. Hope this works.

 

[rotarymike]

put painters/masking tape on the lower and use vice grips to slowly insert the pins...wrap the vice grips with tape as well to ensure the pins arent chewwed up on the ends...thats how i did it...

I do something similar but use channel-locks; that way I can adjust the "closed" size such that I don't pinch the bolt catch pin boss or squeeze the trigger guard area. Tape everything to avoid scratching. I've also done this with a small vise, again padded to a fair-thee-well.

Regarding the bolt catch, it should have a fall-out fit without spring/plunger/pin. If not then the bolt catch is not milspec, or the slot in the lower isn't. If it is difficult with the spring/plunger installed, then look at where they are seating on the catch. Still shouldn't be very difficult to line up. You may want to get the pin started on one side, then you don't have to hold it AND the bolt catch lined up AND the pliers.

 

[Dayman]

I ground it down to sung fit but operable. Should I take more off? I'm hoping they will wear in now. Both are mil spec to my under standing?

 

[rotarymike]

Any manufactured item can be defective. Milspec refers generally to the design, not the implementation (at least on the civilian market. On the DoD market milspec usually specifies allowable tolerances).

Any significant drag on the bolt catch can slow the mag follower from pushing it up in time to catch the cycling bolt. Try some lube in there and see if that smooths it out.

And, well, the bolt catch IMHO isn't a safety item. You can finish the gun and see if it holds open when you shoot it - if it works, great. If it doesn't you can pull it back out and sand it down some more. Nothing should blow up if it doesn't work

 

[Dayman]

Thanks for the help. Think I may take a little more off to smooth it out. Am I ok with the spray paint? Should I have it coated in any thing else? I do shoot my guns in the rain don't want to worry about rust if not coated.

 

[rotarymike]

Get a cold-blueing touch up kit at a sporting goods store, and use that. Paint will wear off faster than even cold blue.

Of course, the best corrosion preventative is oil. And as that is a moving part, it should be lubed regularly (although not drowning in oil).

 

[Dayman]

I am notorious for over oil. I will try to find a cold blue kit. Mabey academy? I'm in greenville. Still gonna try to find a bolt catch tomorrow I think I know where one maybe. Have really enjoyed this despite the frustration. This is a gun I want to keep for my son as the lower mfg. is from where he is born.

 

[rotarymike]

I got my last cold blue kit at Walmart - I think it's a Hoppes branded kit. That has been years though.

One of the best sites for AR assembly I've found: http://www.ar15.com/forums/t_3_4/226782_.html

Although, once you've built one, the rest are easy-peasy. Nothing like headspacing a Mauser

 

[Dayman]

Thanks for the link! I hate I'm new to building, appreciate the knowledge shared.

 

[Dayman]

Ok tried another bolt catch and did not fit. So I called james firearms and dropped the reciever off. They want to measure and said that they had a catch and would install for me. Apparently spikes and cmmg have had fitment issues with the psd lowers, they said they were going to start opening them up a little bit more.

 

[bigfutz]

Receiver wont rust - aluminum. +1 channel locks with taped ends. Also, you can use an old phone book to support various sections while tapping in pins, e.g. trigger guard. Youtube it. You might also find Allen wrenches helpful while inserting spring pins, to hold them in while putting in the pins.

 

[Dayman]

Finished the build... Sort of plan to replace the utg stock with something else. Bad some more issues with the lower the magpul maid grip would wiggle lose and the stock grip with the kit would not engage the safety, I switched the moe magpul grip off my stag and it works great. The maid is now on the stag and fits like a glove. I think I'm gonna hit psa for a complete upper and be done with the build. Thanks for all the help.

 

[rotarymike]

That's really odd. I've never had that sort of fitment issue across 5 brands of receiver and 3 brands of lower parts kit + generic LPKs.

 

[Tigerstripe]

there are 3 springs about the same size for the 2 takedown pins and the saftey. if the stronger spring is not in the saftey it moves too easily.

 

[Dayman]

there are 3 springs about the same size for the 2 takedown pins and the saftey. if the stronger spring is not in the saftey it moves too easily.

I used the correct spring, I thought of that too as I checked against the spring in my stag when I switched grips. Seems in the panic some quality control has suffered, the spikes lpk even had an extra take down spring included. Every thing is together now and I am happy with the finished build (crazy how micrometers will cause parts to not work). James arms fixed my bolt catch issues and were very friendly, I will absolutely use them again (after taking mine in they reported finding and pulling additional errors on some other lowers). Next I think I will test fit my other upper for function. I built this gun to 1. Learn how they work and 2. Save for my son as psd guns are stamped Greer sc and that was where he was born.